--- a/browser/base/content/browser-sync.js
+++ b/browser/base/content/browser-sync.js
@@ -109,31 +109,36 @@ var gSync = {
     }
   },
 
   init() {
     if (this._initialized) {
       return;
     }
 
+    // initial label for the sync buttons.
+    let statusBroadcaster = document.getElementById("sync-status");
+    if (!statusBroadcaster) {
+      // We are in a window without our elements - just abort now, without
+      // setting this._initialized, so we don't attempt to remove observers.
+      return;
+    }
+    statusBroadcaster.setAttribute("label", this.syncStrings.GetStringFromName("syncnow.label"));
+    // We start with every broadcasters hidden, so that we don't need to init
+    // the sync UI on windows like pageInfo.xul (see bug 1384856).
+    let setupBroadcaster = document.getElementById("sync-setup-state");
+    setupBroadcaster.hidden = false;
+
     for (let topic of this._obs) {
       Services.obs.addObserver(this, topic, true);
     }
 
     this._generateNodeGetters();
     this._definePrefGetters();
 
-    // initial label for the sync buttons.
-    let statusBroadcaster = document.getElementById("sync-status");
-    statusBroadcaster.setAttribute("label", this.syncStrings.GetStringFromName("syncnow.label"));
-    // We start with every broadcasters hidden, so that we don't need to init
-    // the sync UI on windows like pageInfo.xul (see bug 1384856).
-    let setupBroadcaster = document.getElementById("sync-setup-state");
-    setupBroadcaster.hidden = false;
-
     this._maybeUpdateUIState();
 
     EnsureFxAccountsWebChannel();
 
     this._initialized = true;
   },
 
   uninit() {
@@ -175,21 +180,16 @@ var gSync = {
   updateAllUI(state) {
     this.updatePanelPopup(state);
     this.updateStateBroadcasters(state);
     this.updateSyncButtonsTooltip(state);
     this.updateSyncStatus(state);
   },
 
   updatePanelPopup(state) {
-    // Some windows (e.g. places.xul) won't contain the panel UI, so we can
-    // abort immediately for those (bug 1384856).
-    if (!this.appMenuContainer) {
-      return;
-    }
     let defaultLabel = this.appMenuStatus.getAttribute("defaultlabel");
     // The localization string is for the signed in text, but it's the default text as well
     let defaultTooltiptext = this.appMenuStatus.getAttribute("signedinTooltiptext");
 
     const status = state.status;
     // Reset the status bar to its original state.
     this.appMenuLabel.setAttribute("label", defaultLabel);
     this.appMenuStatus.setAttribute("tooltiptext", defaultTooltiptext);

--- a/browser/components/places/content/places.js
+++ b/browser/components/places/content/places.js
@@ -1,17 +1,16 @@
 /* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 /* import-globals-from editBookmarkOverlay.js */
 // Via downloadsViewOverlay.xul -> allDownloadsViewOverlay.xul
 /* import-globals-from ../../../../toolkit/content/contentAreaUtils.js */
-/* import-globals-from ../../../base/content/browser-sync.js */
 
 ChromeUtils.import("resource://gre/modules/AppConstants.jsm");
 ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm");
 ChromeUtils.import("resource://gre/modules/TelemetryStopwatch.jsm");
 ChromeUtils.import("resource://gre/modules/Services.jsm");
 ChromeUtils.defineModuleGetter(this, "MigrationUtils",
                                "resource:///modules/MigrationUtils.jsm");
 ChromeUtils.defineModuleGetter(this, "BookmarkJSONUtils",
@@ -172,17 +171,16 @@ var PlacesOrganizer = {
       }
     }
 
     // remove the "Properties" context-menu item, we've our own details pane
     document.getElementById("placesContext")
             .removeChild(document.getElementById("placesContext_show:info"));
 
     ContentArea.focus();
-    gSync.init();
   },
 
   QueryInterface: function PO_QueryInterface(aIID) {
     if (aIID.equals(Components.interfaces.nsIDOMEventListener) ||
         aIID.equals(Components.interfaces.nsISupports))
       return this;
 
     throw Components.results.NS_NOINTERFACE;

--- a/browser/components/places/content/places.xul
+++ b/browser/components/places/content/places.xul
@@ -43,18 +43,16 @@
         persist="width height screenX screenY sizemode">
 
   <script type="application/javascript"
           src="chrome://browser/content/places/places.js"/>
 #ifndef XP_MACOSX
   <!-- On Mac, these are included via macBrowserOverlay.xul -> browser.js -> defineLazyScriptGetter -->
   <script type="application/javascript"
           src="chrome://browser/content/places/editBookmarkOverlay.js"/>
-  <script type="application/javascript"
-          src="chrome://browser/content/browser-sync.js"/>
 #endif
 
   <stringbundleset id="placesStringSet">
     <stringbundle id="brandStrings" src="chrome://branding/locale/brand.properties"/>
   </stringbundleset>
 
 
 #ifdef XP_MACOSX